Don't know anything about AMD System Monitor. Try Core Temp RC6. AMD engineering says they will be fixing AMD Overdrive in the next iteration so it reads temps properly.
Core temp is the only temp that counts and as long as it's below the AMD specified max 24/7 temp you're good to go. While none of the software temp applets are accurate below about 40C on AMD FX CPUs and APUs, in the 40C-70C range, AMD engineering advises they are pretty close.
Technical ignorance is NOT a destiny it is a choice. Do your homework so that you can make technically informed decisions and not be duped by advertising hype or mis-information stated as fact when its not.